Cyclotella mascarenica nov. spec., a new stelligeroid Cyclotella (Bacillariophyceae) from a pond of the Réunion Island (France)

Abstract

A new stelligeroid Cyclotella (Bacillariophyceae), Cyclotella mascarenica KLEE, HOUK et BIELSA nov. spec., from a pond on Reunion Island (France) is described here on the basis of LM and SEM studies. This species is strongly reminiscent of Cyclotella stelligera (CLEVE et GRUNOW) VAN HEURCK, however, it differs from it by thicker ribs, by the fact that inside, each rib is typically forked to a finger-like structure near the valve margin and that the marginal fultoportula is inserted on a rib where this forking begins. Une nouvelle espece de Cyclotella (Bacillariophyceae), Cyclotella mascarenica KLEE, HOUK et BIELSA nov. spec., provenant de l'ile de la Reunion (France) est decrite a partir d'observations au microscope optique et au microscope electronique a balayage. Cette espece est tres proche de Cyclotella stelligera (CLEVE et GRUNOW) VAN HEURCK; elle en differe par des cotes plus epaisses qui se caracterisent interieurement par des extremites bifurquees au voisinage du bord de la valve et par la position de la fultoportula marginale, placee au depart de la bifurcation.